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Topic: Concrete dome (Read 1713 times)

I am in the process of buying a new wood fire oven... I found one which has the dome made out of concrete.As I looked closer there are 2 layer of concrete and in between there is some insulating cotton/foam....

Now I am bit worried that it will not proform as well as the the brick domes.....

I am in the process of buying a new wood fire oven... I found one which has the dome made out of concrete.As I looked closer there are 2 layer of concrete and in between there is some insulating cotton/foam....

Now I am bit worried that it will not proform as well as the the brick domes.....

Does anybody can give me some pointers....

Best regards,Paulo

How sure are you that it is concrete and not a refractory castable? Cotton/foam insulation? I doubt that too...cotton would burn and foam would melt. Most likely ceramic or mineral wool....not sure about the what the ' foam ' could be. Pictures would sure help....lots of bad products out there.

There are a ton of variables as far as what performs better..brick vs cast. The advantage a brick dome has, that being built from unit masonry, cracking in the joints won't weaken the structure like a crack in the middle of a cast panel. Good cast domes have seams to account for expansion and contraction, but that doesn't always stop a panel from cracking....a lot depends on the mix design, how it is used, etc,etc. A brick dome has more flexibility to movement than a cast dome, in relative terms.

I believe regular concrete would be unsuitable with the high temps associated with Neapolitan baking.

It wouldn't be suitable for a fire pit, never mind Neo baking.

Portland is not a refractory material...that's why I'm questioning what the dome is actually made from. If this one is made out of concrete ( opc, sand and aggregate) , then no need to look any further...it is junk and not worth bothering with.

Seems like Paulo's first language is not English. I think pictures are necessary. Ceramic wool is not easy to describe if you don't know what it is. And to a layperson (not bricklayer ) cement vs concrete is a trivial distinction. I have a self-built refractory cement oven and people ask me about my "Cement oven" or "concrete oven" interchangeably.

First thank you for the help everybody.... I am a noob in this subject so any help is appreciated.

Ok, I went to the seller again to take some pictures... He told me that is a special concrete for high heat applications. The wool is like misterchu said ceramic wool which is for the heat insulation on top of that they put a wire net and a second layer of concrete....

I asked him about cracks and he told me that he has the same oven in his house for over ten years and there are cracks but they are very small and do not become bigger 2-2.5mm.. He said this cracks are expansions cracks and will not affect temperature or lifetime of the oven....

Well never their less I would like you guys opinion... As sales people can say a lot...

So here the pictures (sorry some picture are upside down just realised after upload)

Yes, this are the two things which bother me too....the exposed fiber and the groud between the floor tiles.

The idea with the slurry is very good... I guess I could do that....

With the floor I could set a new layer of bricks on top of this one.... Without groud an then have the dome fixed on top of the new layer.... (Would this work??)The only issue is that I would be already paying 1100 US$ for this oven if I start now adding stuff it probably blows my budget.

Visit forno bravo, create an account (free)...download the free oven plans, then consult the board to clarify certain parts of the plans. It is a helpful forum, almost all of the people that built ovens from the plans have never laid a brick in their life. And while the Pompeii oven may not be the greatest design or a true pizza oven, it is a forgiving oven to build.

Adding bricks to the hearth and dome adds thermal mass. Insulation is used outside of the thermal mass to help it hold heat for longer. Insulation is usually a low density material (like the ceramic wool, or perlite-cement mixes often mentioned of here) and would be placed below the hearth and around the dome.